Muammar Gaddafi's son and one-time heir apparent is believed to be heading towards Niger, where his brother and dozens of loyalists have sought refuge.

Rhissa ag Boula, an adviser to Niger's president, said he was in touch with Tuareg who are helping guide Saif al-Islam Gaddafi across the desert from Libya to Algeria and finally to Niger.

The Tuareg were among Gaddafi's strongest supporters, and one of his other sons as well as several of his generals relied on Tuareg guides to reach Niger in September.

Boula said: "If he comes here, the government will accept him, but the government will also need to respect its international obligations. It's up to him to decide [whether to come to Niger]." Saif is one of two surviving regime figures wanted to stand trial for crimes against humanity committed during Libya's protracted battle for power.

Boula, who is Tuareg himself and led a rebellion against the Nigerien government that was reportedly funded by Gaddafi, said Saif appeared to be poised to cross into Algeria on his way to Niger. It would be the same route that his brother al-Saadi Gaddafi and more than 30 other Gaddafi loyalists used in September.

Niger's government has said that members of the Gaddafi regime wanted by the ICC will be turned over to the court.

Al-Saadi, who is not wanted by the ICC but is the subject of a UN sanction, and several other regime figures are under house arrest in Niger's capital. Others are under surveillance but are allowed to leave their villas, Niger's government said.

Because of its large Tuareg population, Niger was among the last countries to recognize the country's new leaders. Mosques and hotels throughout Niger were built by Gaddafi and he remains deeply popular in the nation, making it a natural sanctuary for fleeing members of his inner circle.